Combining ensemble models and connectivity analyses to predict wolf expected dispersal routes through a lowland corridor

Abstract

The Italian wolf (Canis lupus italicus) population has remained isolated South of the Alps for the last few thousand years. After a strong decline, the species has recolonized the Apennines and the Western Alps, while it is currently struggling to colonize the Eastern Alps. Recently, the species was detected in a lowland park connecting the Northern Apennines to the Central Alps. If the park was able to sustain a net wolf dispersal flow, this could significantly boost the connection with the Eastern Alps and the Dinaric-Balkan population. We investigated the suitability of the park as a functional ecological corridor for the wolf through the unhospitable lowland of Northern Italy. We collected wolf occurrence data in two study areas. We modeled species distribution running a separate ensemble model for each study area and then merging the output of the models to obtain an integrated suitability map. We used this map to identify corridors for the wolf adopting a factorial least-cost path and a cumulative resistant kernel approach. The connectivity models showed that only two corridors exist in the lowland areas between the Northern Apennines and the Central Alps. The Western corridor is a blind route, while the eastern corridor passes through the park and has a continuous course. However, the models also revealed a scarce resilience of corridor connectivity in the passageways between the park and the Apennines and the Prealps, which suggests that urgent management actions are necessary to ensure the future functionality of this important corridor.